Some alcoholic beverages are, while stored in barrels, matured for at least 4 to 6 years, generally for 7 to 10 years, but for a longer period of time of about 20 years, like whisky.
During storage, there may occur evaporation and annihilation of unmatured components such as sulfur compounds, etc.; reaction (oxidation, acetalization, esterification, etc.) of new make spirits (fresh whisky)-derived components, decomposition of barrel materials-derived components, reaction of raw material-derived components released in barrels and raw whisky, state change of ethanol and water constituting raw whisky, etc., whereby maturated whisky can come to have taste intrinsic thereto.
However, during storage, raw whisky may be absorbed by barrels or may evaporate through barrels, and therefore the amount of the stored raw whisky naturally decreases. Consequently, prolongation of the storage period causes increase in product loss, from the viewpoint of production efficiency.
Given the situation, a method of proactively removing unwanted components for alcoholic beverages, for example, unmatured components such as sulfur compounds and the like, precipitated components to form in a cold season, unpleasant odor components and others, from alcoholic beverages without waiting for spontaneous change thereof to occur during storage, is taken into consideration.
As a method of removing unwanted components from alcoholic beverages, for example, there have already been proposed a method of bringing alcoholic beverages into contact with an adsorbent prepared by processing silica with an organic silane compound (see PTL 1), a method of bringing alcoholic beverages into contact with activated carbon (see PTL 2), a method of using an ion-exchange resin (see PTL 3), a method of using metal particles and a resin layer (see PTL 4), etc.
However, there is room for further improvement in the above-mentioned prior-art technologies for providing products capable of satisfying quality on a higher level.